Let me guess, you live on the west coast? Usually west coasters believe there is no such thing as lag because their infrastructure is ideal and close to the servers.
Believe me there is lag. I do not only blame it on my bad games, I blame it on my good games too. How can I got 45 kills / 8 deaths one game, and then the very next game go 15/38, and then the very next game go 35/5? My skill hasn't changed. My strategy hasn't changed. The players haven't changed. What has then changed? The only thing that makes sense is lag was on my side, or lag wasn't on my side. There are games where I feel like a god, where the people don't seem to see me for a second or don't react right away. I know this has to be from lag. Then there are games where I am killed by run n' gunners from around corners before they are even visible on my screen. There are games where I've clearly taken cover on my screen, but they killed me when I was standing out in the open. This is from lag. These types of games exist, both good and bad, and those who deny it just don't want to admit that how they performed could be anything other than skill.
Better bandwidth doesn't necessarily ensure you a better gaming experience, however I do notice that my ping is lower with higher bandwidths, and lower ping should get you a better gaming experience. It shouldn't give you an advantage, but it should provide lag-free or near lag-free gaming. Match-making should take into account and match players of similar pings, but it doesn't always work very well.